1. Field
The present invention relates generally to network security and, more specifically, to apparatuses and methods for performing KASUMI ciphering process.
2. Description
Networks enable computers and other devices to communicate. For example, networks can carry data representing video, audio, e-mail, and so forth. However, network systems are subject to many threats, including loss of privacy, loss of data integrity, identity spoofing, and denial-of-service attacks. To address these threats, many measures have been developed and employed to improve the security of network communications. For example, a standard offered by a consortium named “3rd Generation Partnership Project” (3GPP) provides a number of algorithms to improve confidentiality and integrity of network communications. Although the target of the 3GPP standard is mobile communications, its confidentiality and integrity algorithms apply to network communications in general. The heart of the 3GPP confidentiality and integrity algorithms is the KASUMI algorithm.
The KASUMI algorithm is a block cipher algorithm that produces a 64-bit output from a 64-bit input under the control of a 128-bit input key. It includes eight round computations. Although the KASUMI ciphering process can be implemented through software simulations, a hardware implementation of the ciphering process may be more desirable because of the higher processing speed of hardware solutions. It is advantageous when a ciphering process does not significantly slow down data processing speed for network communications. In a hardware implementation, a slow speed of KASUMI computations may require that more than one KASUMI module be used to improve the KASUMI processing speed so that the overall data processing speed of a network system will not be slowed down. More KASUMI modules require a larger physical area in a chip, and thus higher power consumption and higher costs. Therefore, it is desirable to improve the processing speed of a KASUMI hardware implementation.